𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 Quadratic Formula!

Do Now: Solve the formula −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 for the given values. b = 5 c = 4 a = -1 b = 3 3. What is the best movie ever made and why?

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What we know about quadratics so far – a lot! Standard Form Vertex Form Factored Form Completing the Square Factoring Graphing Quadratics

𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 RWA  Dolphin Jumping 𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 https://www.youtube.com/watch?v=g8RoFdyYY3s&t=16s

Uses of Quadratic Formula 𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 To find the roots of a quadratic function. To check your answer if you used another method When you have a function that can’t be factored When you don’t feel like completing the square When a ≠1 When to use Quadratic Formula

Quadratic Formula 𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎

Quadratic Formula Song Don’t stop believing: https://www.youtube.com/watch?v=1FaJshIWdpU Instrumental: https://www.youtube.com/watch?v=1punmUZoNd0 Rap: https://www.youtube.com/watch?v=1FaJshIWdpU 𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎

Steps on using the quadratic formula 𝑥= −𝑏± 𝑏 2 −4𝑎𝑐 2𝑎 Make sure function is in standard form, if not, put it in standard form by moving all terms to one side. Define your a, b, and c. Plug values into formula and solve  be careful using the calculator. *Calculator rules of thumb* ---Always put parentheses around numbers when plugging them in. ---Be careful with your parentheses  don’t forget to close them.

Let’s try it!

Exit Ticket Find the solutions of 2 𝑥 2 +2𝑥+9=5 using the quadratic formula.